A 2009 University of Pennsylvania study found that incentives help when common sense and medical advice fail. The researchers worked with a sample of 878 active smokers who had expressed a desire to quit. Half received only information about smoking cessation programs, while the others were given $750 for enrolling in a program, quitting smoking, and remaining smoke-free for a year.

The cash-incentive group was more likely to enroll in a smoking cessation program, more likely to quit within six months, more likely to remain non-smokers after quitting for six months, and more likely to refrain from smoking for more than a year.

However, for more than 90 percent of the subjects, smoking addiction won out over the incentive. This suggests incentives do work better to promote quitting — for some